(a) Field of the Invention
This invention relates to novel spiroindolone derivatives. More specifically, this invention relates to spiro[cyclopentane-1,3'[3H]-indole]-2'-one derivatives, and to spiro[furan-3(2H),3'(3H)-indol]-2'-one derivatives and their thia analogs, to a process for their preparation, to methods of using the derivatives and to pharmaceutical compositions of the derivatives. These derivatives are useful for treating hypertension in mammals.
(b) Description of the Prior Art
The closest prior art of which applicants are aware is the spiro[cyclopentane-1,3'-[3H]-indol]-2'(1'H)-ones as exemplified by B. Witkop and J. B. Patrick, J. Amer. Chem. Soc., 75, 2572 (1953) having a spiro ring at position 3 of the indol-2-one. However, the prior art compounds lack the substituents on the spirocyclopentane ring, which are characteristic of the compounds of this invention.